title: Effect of ace inhibitors and TMOF on growth, development, and trypsin activity of larval Spodoptera littoralis.
abstract: Angiotensin converting enzyme (ACE) is a zinc metallopeptidase capable of cleaving dipeptide or dipeptideamide moieties at the C-terminal end of peptides. ACE is present in the hemolymph and reproductive tissues of insects. The presence of ACE in the hemolymph and its broad substrate specificity suggests an important role in processing of bioactive peptides. This study reports the effects of ACE inhibitors on larval growth in the cotton leafworm Spodoptera littoralis. Feeding ACE inhibitors ad lib decreased the growth rate, inhibited ACE activity in the larval hemolymph, and down-regulated trypsin activity in the larval gut. These results indicate that S. littoralis ACE may influence trypsin biosynthesis in the larval gut by interacting with a trypsin-modulating oostatic factor (TMOF). Injecting third instar larvae with a combination of Aea-TMOF and the ACE inhibitor captopril, down-regulated trypsin biosynthesis in the larval gut indicating that an Aea-TMOF gut receptor analogue could be present. Injecting captopril and enalapril into newly molted fifth instar larvae stopped larval feeding and decreased weight gain. Together, these results indicate that ACE inhibitors are efficacious in stunting larval growth and ACE plays an important role in larval growth and development.
authors.affiliation: Laboratory of Agrozoology, Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium.
authors.forename: Els
authors.initials: E
authors.lastname: Lemeire
authors.forename: Dov
authors.initials: D
authors.lastname: Borovsky
authors.forename: John
authors.initials: J
authors.lastname: Van Camp
authors.forename: Guy
authors.initials: G
authors.lastname: Smagghe
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology*; D000818:Animals; D002216:Captopril / Q000494:pharmacology*; D005247:Feeding Behavior / Q000187:drug effects; D006458:Hemolymph / Q000378:metabolism; D019476:Insect Proteins / Q000378:metabolism; D007814:Larva / Q000187:drug effects / Q000254:growth & development; D009842:Oligopeptides / Q000494:pharmacology*; D007703:Peptidyl-Dipeptidase A / Q000097:blood / Q000378:metabolism / Q000502:physiology; D018411:Spodoptera / Q000187:drug effects* / Q000254:growth & development; D013379:Substrate Specificity; D014357:Trypsin / Q000096:biosynthesis / Q000378:metabolism
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D019476:Insect Proteins; D009842:Oligopeptides; C065612:Peptide oostatic hormone; D002216:Captopril; D007703:Peptidyl-Dipeptidase A; D014357:Trypsin